How to improve sex crime investigations

Catherine Johnson, a former detective and subject matter expert on sexual violence, shares more than 10 best practices for improving sex crime investigations and public safety response to sexual assault and rape


With only 46% of rapes that occur in the United States being reported to police[1] and only 9% of those reported resulting in prosecution[2], it’s imperative that communities improve public safety response to capture offenders and support victims. The following best practices focus on improving sex crime investigations.

The scene of a rape can be very dynamic with a lot of moving parts. First responders have the responsibility of ensuring the scene is safe, determining if the victim requires medical treatment, preventing the crime scene from being contaminated and attempting to identify and apprehend the offender(s). All of this must be done while trying to approach the victim in a trauma-informed way and providing constant updates to the chain of command.

In addition to these factors, it is common for first responders to have a pre-conceived idea of what they believe occurred. This pre-conceived idea can be as a result of their own bias, or the bias of the officer(s) who trained them. As a result, things may be missed or simply ignored. This can give victims the feeling they are not believed, and thus that their case is not going to be handled properly. When victims do not feel believed or think their case is not being handled correctly, they may withdraw cooperation resulting in offenders not being held accountable. This can also fuel the officer’s initial bias.

I have had the privilege of talking to and working with criminal justice professionals and survivors from all over the world. The problems, challenges and issues surrounding rape investigations are strikingly similar regardless whether they are happening in Ghana or Kansas City. Based on my experience working with both survivors and investigators, it is imperative for investigators to keep an open mind and leave their own biases behind while recognizing what they say and do can impact the direction a case goes, and how the victim is left to feel in their wake.

Adjusting the Mindset of Sex Crimes Investigations

Most recently I spoke to a woman who had been raped in her home by multiple individuals she did not know and did not invite inside. As she described her experience it became clear that, in her mind, the officers that responded had gone to her home with an idea of what they believed occurred and an underlying sense that the victim had something to hide.

The victim said she told the officers about specific items the offenders had touched such as a glass, lubricant and cabinet. The officers did not process or collect the items, but instead utilized fingerprint powder on a light switch when the victim never indicated a light had even been turned on. As a result, the offenders were not identified or captured in a timely fashion and they went on to commit a similar crime against another woman.

While I did not have the opportunity to review this victim’s case file, her anecdotal description helps to illustrate what should be done with each sex crimes investigation.

Best Practices for Successful Investigations

Every case, every time

Investigate each case you are given. Don’t cut corners. Start from the premise that every person who reports a sexual assault deserves a thorough, unbiased investigation. It should not matter if the victim is a wealthy person in a nice home, or a homeless person living under a bridge. Both cases should be given due diligence and handled with the same professionalism and degree of seriousness.

Conduct a victim-centered, offender-focused investigation

To be victim-centered is to focus on understanding the impact of the trauma and making sure their needs are met.

One simple way to do this is to ensure the victim has the option of having a victim advocate present during their interview(s). Victim advocates can be one of the best assets in your investigation as they can provide the emotional support needed which allows the investigator to focus on the facts and difficult questions. Victim advocates can also answer questions about victim’s compensation, counseling options and other resources available to them that are not known to the investigator.

To be offender-focused means focusing on the offender’s actions versus only focusing on the victim’s behavior. For example, if the victim reports she was picked up walking on the street at 2:00 am, it is understood you need to ask why they victim was walking at that time. But it is equally important to also investigate why the offender was out at 2:00 am, why they stopped to pick the victim up and why they committed the crime the victim reported. This leads to including the following types of questions in the sex crime investigation:

  • What kind of criminal history does the offender have? The offender may not have a history of sexual assault, but may have a history of soliciting prostitution, physical assault on women and burglary. Depending on the allegations made, the offender could be increasing their violence.
  • Have there been other reports of people being picked up and victimized in the area that matches this victim’s account? Could this be a serial rapist targeting a vulnerable population? Are there other victims who have not come forward for fear of not being believed?
  • What did the offender have in their car? Is there a weapon or items commonly used to bind a person such as handcuffs, duct tape or rope? Do they have child safety locks engaged which would prevent a person from exiting the vehicle?

These questions are obviously focused on the scenario above, and many more could be listed, but the intent is to demonstrate what it means to be offender-focused.

Begin with the end in mind

I often hear law enforcement officers complain about the prosecutor’s office being “lazy” and “not doing their job.” Prosecutors often complain officers’ investigations are poor and incomplete. I learned early in my career that prosecutors can only prosecute what they are given. Therefore, if they are given a case that only had the bare minimum completed, then they may not be able to take it to trial.

It’s critical to talk to your prosecutors when they decline a case. Ask what needs to be done to make the case more prosecutable, then when you do your next investigation include everything they suggested. Sometimes the answer will be nothing. If the facts do not prove a case beyond a reasonable doubt, then the case will not move forward. However, if an investigator begins to look through the lens of beyond a reasonable doubt, and completes a thorough, unbiased investigation, the facts or an explanation for challenging facts, often exists.

Look for corroboration of statements made by victims, witnesses and suspects. Leave no stone unturned.

Keep an open mind

In my experience, the more outrageous the story the more likely it actually occurred. Understand most allegations of rape are not false, made for revenge or occur because a victim’s feelings are hurt. If you assume something couldn’t have happened the way it was described, or assume the victim is not credible or the offender couldn’t possibly be a rapist then you will miss important evidence and facts because you will be working to prove your theory instead of working to prove what actually occurred.

However, if you start by believing the victim and let the facts drive the investigation, you end up with more evidence which means more thorough case files which will result in more offenders being held accountable.

Avoid developing theories about what occurred before having all of the facts present

As mentioned above going into an investigation with an idea of what you think occurred can result in efforts to prove a theory versus being open to all facts. For example, if you look at a woman with a history of prostitution and assume her report is as a result of a lack of payment for services, you may miss the serial rapist who is targeting that specific population.

Offenders choose their victims, and women being used in prostitution or other vulnerable populations such as drug-addicted, homeless and those with untreated mental illness are often perfect victims in the eyes of an offender because they believe the victim won’t fight back, won’t report or if they do report will be seen as less than credible.

Look at challenging facts through the lens of an offender. Could the challenging facts actually be vulnerability exploited?

Remember that offenders choose their victims

When talking to the victim, they will give you indicators of what an offender may see as a vulnerability. For example, if a victim tells you they were extremely inebriated that could be considered a vulnerability. The next question may be, how inebriated was the suspect? Was this a case of two people who were both drunk and engaged in sexual activity, or was this a case of an offender who was in control using the victim’s inebriation and inability to fight back, perceived lack of credibility and possible inability to remember the crime?

This analysis practice can be used in other areas of vulnerability as well.

Listen to the victim with the intention of hearing and understanding them – not for the purpose of responding

Be fully present during the interview. Listening is actually the most difficult part of an interview because one must shut down that innate sense of wanting to respond, or the thoughts of what needs to be done next.

By actively shutting down your other thoughts and focusing completely on what the victim is saying, the victim will feel they are being heard. By being fully engaged and focusing completely on what the victim is saying investigators may also learn about additional witnesses, evidence or explanations for something they may not have previously understood. The devil is in the details.

It is often the smallest detail, that initially does not seem important that can be the tipping point in the investigation.

Be trauma-informed

Understand trauma and how it relates to a victim’s ability to recall events. Individuals who have experienced trauma may not be able to relay information in a linear fashion and may forget (or simply not have a memory of) certain things. When practical, give the traumatized person 24 to 48 hours before requiring a full statement. Let them provide the information in the way that they remember.

This best practice enables you to get more robust statements, and it allows for fewer inconsistencies.

Realize that inconsistencies are not necessarily intentional lies

As stated above, trauma impacts a person’s ability to recall events. The gaps created in their memory may never return or they may take several days to return. Do not assume because the victim changes the order of events, adds a detail previously omitted or shares additional information they are lying. In some cases, it is trauma that explains the change and in some cases, it is because the investigator has gained the victim’s trust and they now feel safe to share the information. For example, a man initially reports a robbery to law enforcement but later discloses a rape. The rape was not disclosed because the victim was lying, but because the victim felt safe with the investigator.

Take the information without judgement and continue to investigate.

Consider what success looks like in your investigations

Success is not necessarily measured by the closure of cases or rate of prosecution, but instead can be measured by victims feeling they were heard, taken seriously and supported.

Ultimately, be the investigator you would want for yourself or your loved one.



[2] See NAT’L CTR. FOR POLICY ANALYSIS, CRIME AND PUNISHMENT IN AMERICA (1999); See also Cassia Spohn et al., Prosecutorial Justifications for Sexual Assault Case Rejection: Guarding the “Gateway to Justice,” 48 SOCIAL PROBLEMS 206 (2001).

Catherine Johnson is a former detective and subject matter expert with experience in developing and implementing training on violence against women for law enforcement, military, and other multi-disciplinary partners both locally and internationally. She also serves as Secretary on the Board of Directors for End Violence Against Women International. For more information and resources, visit the EVAWI resource library.